About wave cycle: The fuel sender in your fuel tank is always working, even if the boat is not under power. Based on tidal changes and wave motion cycles, the float is constantly moving, whether it be by the boat bobbing in the water, taking sharp turns, or trailering the boat down the highway. This constant movement wears the fuel senders moving parts, creating an expected life cycle for the unit. The best senders are determined by what materials are used to build them, and the amount of moving parts, which together estimate the amount of wave cycles the sender will reach.